Patent GB-807862-A (GB)
Title: Improvements in optical projector units
Inventor: GOODHART GAVIN CAIRD
IPC: G01S7/40
Filed: 1955-11-22
Abstract: 807,862. Warfare teaching. HESEARCH ENGINEERS Ltd., GOODHART. G. A. J., BUCKINGHAM, J., and BURNSIDE, W. Feb. 21, 1957 [Nov. 22, 1955], No. 33458/55. Class 119- Relates to the apparatus for providing synthetic exercises in tactical naval manoeuvres described in Specification 791,037 and in particular to the detailed construction of the optical projector units for projecting the spot of light on to the screen and for projecting an arc of light which emanates from the spot of light and represents a salvo of torpedoes fired from a ship represented by the spot of light. The optical components for projecting the spot of light are mounted in front and rear gimbals 5, 6, Fig. 1, the front gimbal mounting including two vertical posts 7 on which are mounted slides 9 coupled by a transverse rod 10, Fig. 3. A third slide 11 carrying the front gimbal 5 is mounted on the rod 10, thus giving the gimbal 5 transverse and vertical adjustment by means of lead screws 12, 13 in threaded connection with slides 11, 9 respectively. The front gimbal 5 carries a projector lamp housing 14, Fig. 1 for projecting the spot of light and a bracket 19 on the gimbal 5 carries spaced rods 20 which support the casing 21 of a viewing telescope 22, the object lens of which is mounted in the bracket 19. The rods 20 pass through a pair of slides 24 pivotally mounted on the rest gimbal about its horizontal axis. Arranged between the telescope eye-piece and the object lens is a bracket 28 supporting two graticules 29, 30, Fig. 9, graticule 29 being marked with compass points and being fixed while the graticule 30 is calibrated radially in units of distance and is mounted for rotational movement about its centre which coincides with the projected spot of light. The bracket 28 is fixed so that the plane of the graticules is parallel to the vertical and horizontal front gimbal guides and includes the centre of rotation of the rear gimbal. The trainee viewing through the eye-piece will thus obtain accurate reading of both bearing and range relative to his own position of any spot or pattern of light falling on the screen within the field of view of his telescope which is simulating a radar plan position indicator. Fig. 9 shows the driving mechanism for lead screws 12, 13 as described in Specification 791,037. In order to simulate a torpedo attack, a second projector unit is provided to project an arc of light and to cause it to move across the screen at a predetermined speed to represent a salvo of torpedoes. This second unit is a modified form of the main projector unit. A lamp housing 54, Fig. 8, is substituted for the telescope casing 21 and contains a lamp 55 and condenser system 56. Mounted in front of the condenser system are four rotatable graticules 57-60, Fig. 10. As described in Specification 791,037, graticules 58, 59 indicate on the screen the spread of a torpedo salvo whilst graticules 57, 60 indicate the run of the salvo, the movement of the graticules being under the control of a torpedo control unit. The torpedo projector follows the course of the spot of light representing the ship which is to fire the salvo, but once a salvo has been fired, movement of the arc of light is independent of the subsequent movement of the spot of light, the torpedo projector being subsequently re-aligned by reconnection of the motors driving the lead screws. A red filter may be included in the torpedo projector so that the arc of light will not be visible in the viewing telescope used by the trainee, which telescope includes a complementary green filter.